I have a 96 Powerstroke extended cab 2 wheel drive with an automatic. I actually just bought it from an 85 year old man that meticuously babied it. It has 135,000 miles and is like a new vehicle. The fuel mileage figures I have seen from everyday driving is 15 to 17 mpg. It has 4.10 gears. Is this about normal? My brother had a 97 that was exactly the same except it had 3.55 gears and it would get up to 24 mpg on the highway. Gear change is not a real option because I pull a race car in a 28 ft enclosed trailer with tools, fuel, etc. Anything I can do to improve everyday mileage?